Apparatus for rectification of liquid mixtures and/or for . . .

ABSTRACT

An apparatus for rectification liquids and/or for scrubbing of gases has an elongated, horizontally extending, cylindrical process chamber or housing. A liquid and a gaseous phase are passed counter-currently through the apparatus. The liquid is thrown outwardly towards the peripheral housing wall by a rotor extending along the bottom of the housing. Liquid flowing downwards along the peripheral housing wall is collected in an upwardly open channel and the liquid collected therein may be supplied to the rotor via an adjustable slot or opening. Transversely extending, axially spaced guide plates are arranged within the housing so as to define a tortuous path for the gas phase flowing through the housing.

REFERENCE TO RELATED APPLICATIONS

The present application is the national stage under 35 U.S.C. 371 ofinternational application PCT/DK00/00086, filed Mar. 1, 2000 whichdesignated the United States, and which international application waspublished under PCT Article 21(2) in the English language.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

The present invention relates to an apparatus for rectification ofliquid mixtures and/or for scrubbing of gases.

2. Prior Art

Apparatuses for rectification of liquid mixtures and apparatuses forscrubbing of gases function in principle in the same way, namely bycausing the atomised liquid and the gas phase to flow counter-currentlyand thus to come into mutual contact. The reason why apparatuses forrectification and apparatuses for gas scrubbing have usually been builtdifferently is that the reaction between the gas and the liquid phasesis different in the two kinds of apparatuses. In rectification heat andsubstance is transferred between liquid and vapour when the heattransmission coefficient is high. For high viscosity mixtures, however,a high atomising velocity is necessary. In gas scrubbing the washingliquid in an atomised condition and the gas to be purified are caused toflow counter-currently at a high velocity. It has been found, however,that the solid particles entrained by the gas may avoid to come intocontact with liquid and to be removed from the gas when the velocity ofthe liquid droplets is relatively low. In gas scrubbing centrifugalpumps are usually used for atomising liquid which is re-circulated.Because it is rather complicated to use a plurality of scrubber stages,usually only a single stage is used, and then the gas being dischargedfrom the scrubber has only been in contact with a relatively dirtyliquid, which has not been utilised at an optimum.

WO 97/18023 comprises an apparatus including a rotative heattransmission body for evaporating liquids or drying pumpable products.The apparatus comprises a scraper for continuously scraping soliddeposits from the evaporation surface of the rotating heat transmissionbody. It has been found that when such a rotative heat transmission bodyis used for treating a mixture of liquid having different boiling pointsand a rotating atomising device is used for throwing droplets on to theevaporation surface of the heat transmission body, a rotating movementis also imparted to the vapour generated. Consequently, an exactcounter-current movement between the two phases can not be obtained, andthis is necessary to obtain an efficient rectification or scrubbing.

WO 91/01784 discloses an apparatus for rectification and gas scrubbing.Liquid is repeatedly thrown through the gaseous phase against an innerperipheral heat transmission surface. Spraying or atomising the liquidby means of a rotor causes a pressure reduction where the liquiddroplets leave the rotor and a corresponding pressure increase where thedroplets are stopped. The pressure difference so created may partly beequalised by transverse gas flows at the end walls of the processingchamber and by a resulting axial flow within the apparatus impairing theefficiency of the apparatus.

The pumping effect caused by the liquid droplets being thrown radiallyoutwardly by the atomising rotor is volumetrically far greater than thevolume of the vapour flowing through the apparatus. The adverse resultis that liquid droplets being thrown radially outwardly adjacent to anoutlet for remanence come into contact with vapour having a relativelyhigh content of the volatile component, and due to the equilibriumbetween the two phases the remanence will have a higher content of thevolatile component than necessary. It is true that the evaporated vapourbeing exhausted through a vapour outlet at the other end of theapparatus adjacent to the inlet of the raw product to be processed has ahigh content of the volatile component. However, when it is mixed withre-circulated vapour the concentration of the volatile component of thedistillate is reduced.

OBJECT AND SUMMARY OF THE INVENTION

The calculation of the dimensions of an apparatus is normally based on avapour flow rate of about 1 m/sec. When, for example, the specificweight of the vapour phase is 1 kg/m³ a pressure difference of only 0.05kg/m² and 0.82 kg/m² (equal to 0.82 mm water column) is necessary forobtaining a vapour flow rate of about 1 m/sec. and 4 m/sec.,respectively. Thus, a very small pressure increase may cause asubstantially re-circulation of the vapour whereby the efficiency isreduced. Therefore, it would be advantageous to be able to obtain a moreefficient control of the vapour flow through the apparatus.

This problem is solved by the present invention. Thus, the presentinvention provides an apparatus for rectification of liquid mixturesand/or for scrubbing of gases, said apparatus comprising an elongatedprocessing chamber extending in a substantially horizontal direction,means for supplying liquid into the processing chamber at a first endthereof, means for discharging liquid from the processing chamber at anopposite second end thereof, liquid application means, which may, forexample, include a rotor, extending along at least a major part of thelength of the chamber for repeatedly throwing supplied liquidtransversely to the longitudinal axis of the processing chamber, meansfor supplying gas into the processing chamber at said second end, andmeans for discharging gas from the processing chamber at said first endso as to obtain a generally counter-current movement of liquid and gasthrough the processing chamber, and the apparatus according to theinvention is characterised in that the processing chamber is dividedinto interconnected sections or stages by means of a plurality of guideplates each extending across a major part of the cross-section of theprocessing chamber.

The guide plates provided in the apparatus according to the inventioncounteract the undesired axial re-circulation of gas phase due to thesmall radial pressure difference caused by the liquid being thrownradially outwardly towards the inner wall of the processing chamber asexplained above. Thus, the guide plates render it possible to obtain astepwise, controlled axial flow of the gas phase.

The processing chamber is preferably defined by a peripheral wall, suchas a horizontally extending cylindrical wall, and a pair of opposite endwalls. Preferably, at least one of the end walls comprises a releasableend wall part covering an opening, which is defined in the upper part ofthe end wall, said opening have dimensions sufficient to allow insertionof guide plates into the chamber through such opening. The opening inthe end wall may be used not only as a usual man hole, but also forinserting guide plates into and removing guide plates from theprocessing chamber, whereby the apparatus may be adapted to perform adesired task at an optimum.

The releasable end wall part covering said opening may be releasablyfastened to the respective end wall in any suitable manner. In thepreferred embodiment, however, the releasable end wall part is in theform of a cover with a flange, which may be connected to the end wall byscrews or bolts. The guide plates may be fastened in position within theprocessing chamber in any suitable manner, for example by welding. Inorder to facilitate changes in the arrangement of guide plates the innerperipheral wall of the processing chamber may comprise means forreleasably fastening the guide plates at any of axially spaced,predetermined positions. Such releasable fastening means may, forexample, comprise annular flanges fastened to and extending radiallyinwardly from the inner peripheral chamber wall. Thus, a larger numberof such predetermined positions may be prepared even though only asmaller number thereof are normally used.

The liquid application means or device may comprise a rotor defining aplurality of liquid collecting pockets or chambers opening in thedirection of rotation. Such pocket may have a U-shaped cross-section andthe width of the opening, the depth of the pocket and the inclination ofthe side surfaces of the U-shape may then be selected so as to obtainthe desired performance.

The rotor may be arranged at the bottom of the processing chamber whereliquid having been thrown against the peripheral wall of the processingchamber be collected for recirculation. The lower part of the rotor maythen dip into the liquid. This may, however, cause undesired vibrationsof the liquid. In the preferred embodiment the liquid application meanscomprise a liquid receiving chamber for receiving liquid flowingdownwards along the inner peripheral wall of the processing chamber, thereceiving chamber communicating with the liquid channel via anadjustable, longitudinally extending opening or slot. In this manner theflow of re-circulated liquid to the rotor may be controlled andstabilised. The liquid receiving chamber, may for example, be definedbetween the peripheral inner wall of the processing chamber and a flapor plate member, which is pivotal about a longitudinal axis so as toallow adjustment of a space defined between the lower edge of the flapmember and the adjacent part of the inner wall of the processingchamber. This allows for the desired control of the liquid supply in avery simple manner. The flap or plate member and the adjacent part ofthe peripheral wall may define an upwardly open liquid collectingchannel allowing for the desired axial transport of liquid through theprocessing chamber.

The guide plates may be shaped and arranged in any suitable mannerpreventing the undesired axial gas flow due to the pressure differencecaused by the liquid being thrown by the rotor as explained above. Thus,consecutive guide plates may be formed and arranged so as to force gasflowing from the gas supplying means to the gas discharge means tofollow a tortuous path and to flow in opposite, transverse directions.As an example, axially spaced consecutive guide plates may extend fromopposite sides of the chamber in overlapping relationship.Alternatively, the guide plates may comprise annular plates eachdefining a central opening and intermediate plates, each of which ispositioned between a pair of annular guide plates and covers the centralopenings.

At least some of the guide plates may define or comprise conduits forheating or cooling fluid, whereby they may function as heating orcooling panels.

In order to remove precipitated solid matter or solid matter formed inany other way the apparatus may further comprise conveyor means forremoving such solid matter separated in the processing chamber from thebottom part thereof. Such conveyor means may, for example, comprise ascrew conveyor including a cylindrical housing communicating with thelower part of the processing chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described with reference to thedrawings, wherein

FIG. 1 is a cross section of an embodiment of the apparatus according tothe invention,

FIG. 2 a is a horizontal, longitudinal sectional view of the apparatusshown in FIG. 1,

FIG. 2 b is a partial sectional view corresponding to that shown in FIG.2 a, but in a modified embodiment of the invention,

FIG. 3 is a vertical sectional view of the embodiment shown in FIGS. 1and 2 a,

FIG. 4 is a cross-section of an embodiment having a conduit for acooling or heating medium arranged on a guide plate,

FIGS. 4 a and 4 b illustrate details of the apparatus, and

FIG. 5 is a vertical longitudinal section of the apparatus shown in FIG.4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) OF THE INVENTION

The embodiments of the apparatus according to the invention shown in thedrawings comprise a preferably cylindrical housing 1 having asubstantial horizontal, longitudinal axis. A liquid application deviceor atomising device 2 a is arranged within the housing and includes arotor 2 rotatably journalled in housing end walls 3 at the bottom of thehousing. The lower part of the end walls 3 is formed as an integral partof the housing, while the upper parts of the housing end walls are inthe form of covers 4 which may be bolted or otherwise releasablyfastened to flanges 6. The end covers 4 are provided with a vapour inlet10 and a vapour outlet 11. The vapour inlet 10 may be connected to anevaporator section (not shown) and the vapour outlet at the opposite endmay be connected to a condenser (not shown) or possibly to the suctionside of a heat pump. The housing 1 is divided into sections or chambersby means of axially spaced guide plates 7, 8 or 9. The end openingscovered by the covers 4 have dimensions allowing the guide plates to beinserted into the housing 1 therethrough. This means, that the apparatusmay be tested without guide plates, and that the guide plates maysubsequently be mounted. The openings covered by the covers 4 may alsoserve as ordinary manholes.

As shown in FIG. 3, an inlet 14 for a raw liquid product to be treatedis arranged at the bottom of the housing 1 at the end of the housing,which is provided with the vapour outlet. An outlet 12 for remanence isarranged at the bottom of the container at its opposite end. In casereflux is used the reflux may be supplied through the inlet 14 and theraw product to be treated may then be supplied through an inlet 13positioned between the inlet 14 and the outlet 12.

In the embodiment shown in FIGS. 1, 2 a and 3, the guide plates compriseaxially spaced pairs of plates 7 and 8 extending from opposite sides ofthe peripheral wall 5 of the housing and defining a central openingthere between. A vertical, substantially rectangular guide plate 9 isarranged between consecutive pairs of guide plates 7 and 8 so as tocover and extend transversely beyond the central openings defined by theplates 7 and 8. Openings are defined between the peripheral housing wall5 and the opposite sides of each guide plate 9. The area of the openingdefined between each pair of plates 7 and 8 is preferably substantiallythe same as the combined areas of the openings defined on opposite sitesof each guide plate 9 and of the cross-sectional area defined betweenconsecutive, axially spaced guide plates.

Liquid droplets being thrown out from the atomising rotor 2 definecarpet-like patterns 15. The thrown out droplets obtain a velocity anddirection being the sum of the vector defining the peripheral velocityof the rotor and the vector defining the rate at which the liquid flowsacross the outer edge 16 of a rotor pocket 22. From this position theliquid will continue in the said direction towards the peripheralhousing wall 5. On this basis it may be calculated how long time it willtake before a droplet reaches the inner surface of the peripheral wall 5and how much the angular position of the rotor has changed in this timeperiod. By such calculations the inner and outer ends or the carpet-likepattern 15 may be determined. Intermediate points of the pattern may becalculated in the same manner, but further factors are influencing theshape of the pattern. Therefore, the droplet patterns 15 illustrated inFIG. 1 are based on observations made when exposed to stroboscopiclight. It is then possible clearly to watch the development of theprocess within the processing chamber and the varying volumes definedbetween the rotating carpet-like patterns 15 of droplets, and the needfor a controlled axial flow of the vapour is evident.

The inner diameter of the peripheral housing wall is preferably selectedsuch that the flow rate of the gas phase or vapour in an inward and anoutward direction between the guide plates is about 1 m/sec. If, forexample, the diameter of the housing wall is about 1.25 m it will take0.5 m: 1 m/sec=0.5 sec. for a particle to move outwardly from the centrein a horizontal plane, and in this period the vapour or gas phaseseveral times comes into contact with liquid when passing a carpet-likepattern 15 of liquid droplets. If, for example, the atomising rotor 2rotates at 9.5 revolutions/sec. and the rotor is provided with 8 pocketsthe gas phase or vapour will come into contact with a carpet-likedroplet pattern 38 times when passing transversely through a passagedefined between a pair of guide plates (corresponding to a columnbottom). As seen in FIG. 2, the carpet-like patterns 15 of liquiddroplets between a pair of guide plates 7 and 8 define gas or vapourvolumes, which at first are increased and subsequently are decreased.Therefore, the liquid droplets are forced to penetrate into the gas orvapour volume whereby an almost complete equilibrium between liquid andvapour is obtained. Thus, the distance between two consecutive pairs ofguide plates 7 and 8 represents two column bottoms with high efficiency.

In the embodiment shown in FIG. 2 a the droplets forming a pattern 15starts in the passage 17. In this passage the vapour or gas flows fromthe centre outwardly towards the peripheral housing wall 5 and is thenreversed so as to flow backwards towards the centre on the other side ofthe rectangular guide plate 9. Thus, the gas or vapour will first flowcounter-currently to the liquid thrown out by the rotor 2 and thenconcurrently when flowing back towards the centre. Therefore, when thegas or vapour is flowing outwardly the patterns 15 of droplets arecounteracting the gas flow, while the patterns or droplets will promotethe flow of gas or vapour towards the centre of the apparatus. However,because the carpet-like pattern 15 is moving at a velocity considerablyhigher than the flow rate of the gas of vapour the dragging along of thegas, when flowing concurrently, can compensate for a substantial part ofthe pressure loss when flowing counter-currently, and the resultingpressure loss for each pair of associated “column bottoms” willtherefore be small and the system will be suited for operation inconnection with a heat pump.

With the arrangement of guide plates 7-9 described above the vapour isdivided into oppositely directed flows 17 and 18 whereby an optimumutilisation of the total volume of the housing 1 is obtained.Alternatively, the guide plates 20 and 21 may be arranged as shown inFIG. 2 b, whereby a single, undivided flow of vapour or gas, which isalternately counter-current and concurrent with the carpet-like patterns15 of liquid droplets, is obtained. In each single transverse passagedefined between the guide plates 20 and 21 and representing a columnbottom the double number of contacts between liquid and vapour isobtained compared to the embodiment described above. However, theapparatus will then be larger. The guide plates 20 and 21 arealternatingly fastened to opposite sides of the peripheral housing wall5. The guide plates 20 and 21 may have an outline as a segment of acircle so that an axial passage is defined between a vertical, linearedge of each guide plate and an adjacent part of the peripheral housingwall 5. The area of this axial passage is preferably substantially thesame as the cross-sectional area of the passage defined between adjacentguide plates 20 and 21.

The guide plates may be releaseably fastened to narrow rings or annularflanges 37, which are welded to the inner surface of the peripheralhousing wall 5. In most cases it is desirable to allow fastening of theguide plates with a relatively small axial spacing. This may be obtainedby means of a fastening arrangement as that shown in FIGS. 4 a and 4 b.The annular flanges 37 welded to the peripheral housing wall 5 have arelatively small radial width and a relatively small thickness, and theouter dimension of the guide plates 7-9 corresponds—with a suitableclearance—to the inner diameter of the welded annular flange 37. Theguide plates may be releasably fastened by means of a separate ring 38having threaded holes formed therein, and releasable fastening members39 comprising screws or bolts for clamping a guide plate and a fixedannular flange 37 between the separate ring 38 and an oppositelyarranged abutment member co-operating with screws or bolts.

As illustrated in FIG. 4, the liquid application device 2 a comprises arotor 2 which is made from a central tubular body, and longitudinallyextending liquid throwing devices defining the open, U-shaped pockets 22are welded to the outer surface of the tubular body. The rotor 2 ispositioned such that part of each liquid throwing device is dipped intoliquid collected at the bottom of the housing or processing chamber. Themaximum depth 24 to which the front edge 16 of each liquid throwingdevice is dipped into the liquid determines the amount of liquidreceived in each of the U-shaped pockets and also the power necessaryfor throwing the liquid from the rotor. Such power is also used forcontrolling the amount of liquid within the apparatus.

The liquid thrown out comes into contact with the gas phase and thenhits the inner surface of the peripheral housing wall 5, and the partfirst being thrown out will then flow down into an upwardly open channel25 serving to stabilise the transverse liquid flow to the atomisingrotor and to allow for the axial liquid flow through the apparatus. Thechannel 25 is defined between a flap member or plate member 26 extendingalong the total length of the housing and by the adjacent part of theinner housing wall 5. The lower edge 27 of the flap member is positionedclose to the bottom of the housing so as to define an adjustable spacingor slot 28 between the lower edge 27 and the adjacent part of theperipheral wall 5. The upper edge 29 of the flap member 26 is pivotallymounted by means of lugs 32 extending inwardly from the peripheralhousing wall 5. The dimensions and the position of the flap member 26 issuch that the size of the channel cross section is sufficient to allowaxial flow of the liquid through the housing involving a necessarylowering of the liquid level. The liquid level will also vary inresponse to the adjustment of the width of the slot 28. The width of theslot 28 may be adjusted by means of an adjusting device 30 shown in FIG.4 b. However the adjusting device may also be made in any other suitablemanner.

The flow of liquid from the pockets 22 will start as soon as the liquidreaches the front edge 16 of the liquid throwing device. If the pockets22 are completely filled, the throwing of liquid will start immediately,and the first part will hit the oblique flap member 26. Due to itsinertia the liquid will continue to flow over the upper edge 29 of theflap member and down into the channel 25. It is preferred that the rotorpockets 22 be filled only to such an extent that the liquid first beingthrown out from the pockets will almost clear the flap member or platemember 26. The width of the slot 28 may be adjusted such that thepockets 22 are not filled too much.

The amount of liquid being atomised varies to a high extent in responseto the extent to which the rotor 2 is immersed into the liquid. Thus, achange of the liquid level of only a few millimeters gives rise to avery substantial change of the amount of liquid being atomised.Therefore, the difference in liquid level, which can be tolerated alongthe length of the housing, is not sufficient to secure the desired axialflow of liquid through the apparatus. This problem is solved by theprovision of the channel 25 in which a decreasing liquid level along thelength of the channel does not give rise to problems.

Because of the efficient contact between the liquid and the gaseouscomponents an apparatus of the type described is also suitable for useas a gas scrubber. By using a multi-stage apparatus the necessary amountof washing liquid may be considerably reduced. In addition, the gasleaving the last stage comes into contact with fresh washing liquid.

When the apparatus is used as a scrubber it may often be an advantagealso to cool the gas flowing through the apparatus. In order to allowsuch cooling the guide plates may define passages therein for a coolingfluids, or the cooling fluid may be passed through a conduit arrangement33 mounted on the guide plates. Guide plates having passages formedtherein may suitably be used when the difference between the pressure ofthe cooling fluid and the pressure within the scrubber is moderate.However, when the desired temperature is such that it is necessary touse a refrigerator system including a mechanical heat pump the necessarystrength of the heat transmission surface may more easily be obtained byusing a conduit arrangement 33. This arrangement is shown onlyschematically because the need for cooling/heating may varysubstantially depending on the problem to be solved. As an example, heatsupply may be desirable when a heat pump is used in connection withrectification, wherein the energy supplied as the power consumption ofthe heat pump may be insufficient to compensate for loss of heat to theambience, or loss of heat due to lacking condensation heat when an extrafraction is taken out. In such case the conduit arrangement 33 mayfunction as an evaporator and be placed in connection with the firststage, because the vapour developed must contribute to therectification. In case of gas scrubbing there is preferably a need forcooling and it may then be advantageous to distribute the coolingconduits over a plurality of the guide plates.

When scrubbing a gas flow containing solid particles as well as bytreating a mixture of gas and vapour, wherein the vapour components maybe condensed by cooling and be precipitated as solids at the lowertemperature, problems may arise to obtain an axial transport of thesolid particles. Providing a screw conveyor 34 below the bottom of thehousing 1 may solve this problem. The screw conveyor 34 is arrangedwithin a tubular housing 35 and is communicating with the lower part ofthe scrubber housing along the total length thereof. Thus, precipitatedor sedimented particles or salts may move into the conveyor housing 35and be transported to an outlet 36 for solids by means of the slowlyrotating conveyor screw 34. The arrangement operates more efficientlywhen the mixture of washing liquid and solid particles is removed at thelowest possible temperature. The maximum heat transfer will take placeat the inlet 10 for the hot gas. Furthermore, it is important thatscrubbing takes place with washing liquid being as clean as possible atthe outlet 11 for the cleaned gas. Therefore the best position for theoutlet 36 for liquid and solid particles is about the middle of theapparatus or housing. Because minor precipitation may take place also inthe later half of the housing the pitch of the conveyor screw 34 must beoppositely directed. In FIG. 5 the washing liquid is supplied to theapparatus at 40.

1. An apparatus for rectification of liquid mixtures or for scrubbing ofgases, said apparatus comprising an elongated processing chamberextending in a substantially horizontal direction, means for supplyingliquid into the processing chamber at a first end thereof, means fordischarging a liquid from the processing chamber at an opposite, secondend thereof, liquid application means arranged at the bottom of theprocessing chamber and extending along at least a major part of thelength of the chamber for repeatedly throwing supplied liquidtransversely to the longitudinal axis of the processing chamber, meansfor supplying gas into the processing chamber and means for discharginggas from the processing chamber so as to obtain a generallycounter-current movement of liquid and gas through the processingchamber, the liquid application means comprising a rotor defining liquidcollecting pockets or chambers opening in the direction of rotation,wherein the liquid application means further comprise an upwardly openliquid channel extending axially along the lower part of the processingchamber and having opposite ends, which are in communication with theliquid supplying means and the liquid discharging means, respectively,at least the lower part of the rotor being arranged within the liquidchannel, wherein the liquid application means comprise a liquidreceiving chamber or channel for receiving liquid flowing downwardsalong the inner peripheral wall of the processing chamber, the receivingchamber communicating with the liquid channel via an adjustable,longitudinally extending opening or slot, wherein the liquid receivingchamber is defined between the peripheral inner wall of the processingchamber and a flap or plate member being pivotal about a longitudinalaxis so as to allow adjustment of a space defined between the lower edgeof the flap member and the adjacent part of the inner wall of theprocessing chamber.
 2. An apparatus according to claim 1, wherein theliquid collecting pockets or chambers have a U-shaped cross-sectionopening in direction of rotation and being adapted to throw the liquidfrom said opening so as to form rotating carpet-like patterns ofdroplets extending from the outer edge of the opening of each saidpocket or chamber towards the inner wall of the processing chamber. 3.An apparatus according to claim 1, wherein the processing chamber isdefined by a peripheral wall and a pair of opposite end walls, at leastone of the end walls comprising a releasable end wall part covering anopening, which is defined in the upper part of the end wall, saidopening having dimensions sufficient to allow insertion of guide platesinto the chamber through such opening.
 4. An apparatus according toclaim 1, wherein the releasable end wall part is in the form of a coverwith a flange connected to the end wall by screws or bolts.
 5. Anapparatus according to claim 1, wherein the processing chamber isdivided into interconnected sections or stages by means of a pluralityof guide plates each extending across a major part of the cross-sectionof the processing chamber, the guide plates formed and arranged so as toforce gas flowing from the gas supplying means of the gas dischargemeans to follow a tortuous path and to flow in the opposite, transversedirections.
 6. An apparatus according to claim 4, wherein the innerperipheral wall of the processing chamber comprises means for releasablefastening said guide plates at any of axially spaced, predeterminedpositions.
 7. An apparatus according to claim 5, wherein the releasablefastening means comprises annular flanges fastened to and extendingradially inwardly from said inner peripheral chamber wall.
 8. Anapparatus according to claim 1, wherein at least some of the guideplates define or comprise conduits for a heating or cooling fluid.
 9. Anapparatus according to claim 1, further comprising conveyor means forremoving solid matter separated in the processing chamber from thebottom part thereof.
 10. An apparatus according to claim 8, wherein theconveyor means comprise a screw conveyor including a cylindrical housingcommunicating with the lower part of the processing chamber.
 11. Anapparatus for rectification of liquid mixtures or for scrubbing ofgases, said apparatus comprising an elongated processing chamberextending in a substantially horizontal direction, means for supplyingliquid into the processing chamber at a first end thereof, means fordischarging a liquid from the processing chamber at an opposite, secondend thereof, liquid application means arranged at the bottom of theprocessing chamber and extending along at least a major part of thelength of the chamber for repeatedly throwing supplied liquidtransversely to the longitudinal axis of the processing chamber andmeans for supplying gas into the processing chamber and means fordischarging gas from the processing chamber so as to obtain a generallycounter-current movement of liquid and gas through the processingchamber, the processing chamber being defined by a peripheral wall and apair of opposite end walls, at least one of the end walls comprising areleasable end wall part covering an opening, which is defined in theupper part of the end wall.
 12. An apparatus for rectification of liquidmixtures or for scrubbing of gases, said apparatus comprising anelongated processing chamber extending in a substantially horizontaldirection, means for supplying liquid into the processing chamber at afirst end thereof, means for discharging a liquid from the processingchamber at an opposite, second end thereof, liquid application meansarranged at the bottom of the processing chamber and extending along atleast a major part of the length of the chamber for repeatedly throwingsupplied liquid transversely to the longitudinal axis of the processingchamber and means for supplying gas into the processing chamber andmeans for discharging gas from the processing chamber so as to obtain agenerally counter-current movement of liquid and gas through theprocessing chamber, the processing chamber being divided intointerconnected sections or stages by means of a plurality of guideplates each extending across a major part of the cross-section of theprocessing chamber, wherein at least some of the guide plates define orcomprise conduits for a heating or cooling fluid.
 13. An apparatus forrectification of liquid mixtures or for scrubbing of gases, saidapparatus comprising an elongated processing chamber extending in asubstantially horizontal direction, a liquid supplying device extendingto the processing chamber at a first end thereof, a liquid dischargingdevice extending from the processing chamber at an opposite, second endthereof, a liquid application device arranged at the bottom of theprocessing chamber and extending along at least a major part of thelength of the chamber for repeatedly throwing supplied liquidtransversely to the longitudinal axis of the processing chamber a gassupplying device for supplying gas into the processing chamber and a gasdischarging device for discharging gas from the processing chamber so asto obtain a generally counter-current movement of liquid and gas throughthe processing chamber, the liquid application device comprising a rotordefining liquid collecting pockets or chambers opening in the directionof rotation, wherein the liquid application device further comprises anupwardly open liquid channel extending axially along the lower part ofthe processing chamber and having opposite ends, which are incommunication with the liquid supplying device and the liquiddischarging device, respectively, at least the lower part of the rotorbeing arranged within the liquid channel, wherein the liquid applicationdevice comprises a liquid receiving chamber or channel for receivingliquid flowing downwards along the inner peripheral wall of theprocessing chamber, the receiving chamber communicating with the liquidchannel via an adjustable, longitudinally extending opening or slot,wherein the liquid receiving chamber is defined between the peripheralinner wall of the processing chamber and a flap or plate member beingpivotal about a longitudinal axis so as to allow adjustment of a spacedefined between the lower edge of the flap member and the adjacent partof the inner wall of the processing chamber.